docs: def _get_raw_key(self, key_id):
          """Returns a static, randomly-generated symmetric key for the specified key ID.
  
          :param str key_id: Key ID
          :returns: Wrapping key that contains the specified static key
          :rtype: :class:`aws_encryption_sdk.internal.crypto.WrappingKey`
          """
          try:
              static_key = self._static_keys[key_id]
          except KeyError:
              static_key = os.urandom(32)
              self._static_keys[key_id] = static_key
          return WrappingKey(
              wrapping_algorithm=WrappingAlgorithm.AES_256_GCM_IV12_TAG16_NO_PADDING,
              wrapping_key=static_key,
              wrapping_key_type=EncryptionKeyType.SYMMETRIC,
          )